The covalent addition of methyl groups to cytosine has become an intensively researched epigenetic DNA marker. The vast majority of technologies used for DNA methylation analysis rely on a chemical reaction, the so-called “bisulfite-treatment”, which introduces methylation-dependent sequence changes through selective chemical conversion of non-methylated Cytosine to Uracil. After treatment, all non-methylated Cytosine bases are converted to Uracil but all methylated Cytosine bases remain Cytosine. These methylation dependent C-to-U changes can subsequently be studied using conventional DNA analysis technologies.